An audio reproduction device (so-called audio amplifier) is a device which supplies a supply signal obtained by amplifying an input signal to a speaker device to drive a speaker so that a sound is reproduced by the speaker device. On the other hand, it is known that, even if an identical signal is input from the audio reproduction device to a speaker device, the sound reproduced by the speaker device varies depending on the structure of the cabinet, for example, the cabinet is of the bass reflex type or the sealed type, or the kind of the speaker mounted to the cabinet. In other words, the speaker devices have their respective characteristics depending on the kinds of the speaker devices. Therefore, it is difficult for a speaker device connected to an audio reproduction device to realize an ideal characteristic by itself. Accordingly, some audio reproduction devices electrically correct the signal to be supplied to a speaker device.
PTL1 discloses an audio amplifier. For example, the audio amplifier disclosed in PTL1, in a speaker device having two kinds of speakers, has a filter means that processes an input signal based on a correction characteristic of impulse response of each of the speakers to correct a phase shift of a sound wave radiated from a driving surface of each of the speakers. With this feature, this audio amplifier can obtain a flat frequency characteristic of the sound reproduced by the speaker device.